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J. H. FLYNN Aug. 6, 1957 DUAL FLAME BAND OVEN BURNER WITH PILOT CROSSOVER Filed April 19, 1955 3 Sheets-Sheet l INVENTOR.

JOHN H. FLYNN MM ATTORNEYS i .1. iilyfflffff i .1525? 5 1. nNJJMpMHQJHMdJ "no 3 2%..36354?! J. H. FLYNN Aug. 6, 1957 DUAL FLAME BAND OVEN BURNER WITH PILOT CROSSOVER Filed April 19, 1955 3 Sheets-Sheet 2 78 oo oooozgooooopo 00 000000 oooooo o INVENTOR. BY JOHN H. FLYNN Jig 9 ATTORNEYS Aug. 6, 1957 J. H. FLYNN 2,801,686

DUAL FLAME BAND OVEN BURNER WITH PILOT CROSSOVER Filed April 19, 1955 3 Sheets-Sheet 5 IN VENT 0R.

JOHN H. FLYNNi ATTORNEYS United States Patent it r in 14 Claims. (Cl; 158-115) This invention relates to gas burners oi the so -called ribbon type, and particularly to, burners of this type adapted to provide two or more spaced ribbons or bands of flame frorn a single burner body.

As is well known in the artr ribbon burners comprise in general a hollow casting forming a,casing,or housing.

adapted to be supplied with a combustible gaseous fuel mixture which is permitted to issue through ports extending longitudinally of the, burner body and, is ignited upon emergence from theseports to provide the aforesaid ribbons of flame. Burnersof this type, but providing only a singleribbon offlame, are disclosed, for. example inmy. prior, Patents Nos. 2,499,482, issued March], 1950, and 2,600,160, issued June 10, 1952. Forincreasedheating. capacity, dual or multiple flame ribbon burnersareoiten desirable, and are commonly 11 for example, as the heating units in ovens of thetraveler or continuous type for baking biscuits, crackers, bread and thelike from.

dough material transported through the oven on conveyor bands. Each individual burner is disposed across the width of the oven, that is, transversely of the direetion of travel ofthe conveyor band, to provide ar' even distribution of heat thereacross,,and a series of theseburnersis arranged in side-by-side relation along, thelength of ihe oven to maintain the desired heating eifect throughout its extent. Sinceovens of this type mayattain considerabie length, as much for, example as two hundred and fifty feet or more, a large number of burners may be required. Each of these burners must have means for igniting the gas issuing from its ports, and where there are two or more spaced ports, as in the case of the burnershere under consideration, ignition means for. both. such ports must.

be. P ed,-, sh n nfl par n lect ode e erally used for this purpose and, inorder to reduse the number of such electrodes required in an installation, it has heretoforebeen proposed to provide but one electrode perburner, to ignite thegas at one main burnerportand to in corporatein the burner, crossover means for causing propagation ofthe. flame from such firse mainport across the intervening body of the. burner to the. other port spaced, from the first. While, as just stated, such acrossover arrangement has been proposed heretofore, it is subject to certain serious disadvantages, particularly with. respect to 121,01 Of Sufficient. structural rigidity under sus tained operation at thehigh temperatureto which such burners are necessarily subjected. Since the;burners are suspended. between longitudinal frame members in the.

oven, and; owing to the construction and arrangement of the cross-over pilot arrangement heretofore employed, such prior burners have had a pronouncedtendency to warp or sag in the middle afterrelatively short periods of use. This resultsin uneven heat distribution across-the oven and leads to the. need for frequent. replacement of the burners, all at substantial expense. Such prior burners have a, further disadvantagein that they produce. a=continuous zone or area of overheating owing to the unvaryingposition it throughout the oven" of the crossover pilot flame, resulting in further unevenness in operation ofthe oven.

Accordingly it is a general objeetof this invention to provide an improved multiple port ribbon burner and integral crossover pilot construction, whereby, upon ignition at a first main port of the ribbon burner, propagation of the flame across the intervening body of the. burner to a second main port will beensured under all conditions.

Because of the obvious .hanard involved should gas issuing fi'orn one main burner port fail to beignited promptly on issuing from the burner port, absolute. dependency of cross-piloting is essential. This must be true for all possible starting conditions of the burner, ranging from lowturndown or standby to maximum heat output condition. Burners of the type disclosed herein areoutstanding in their eliectiveness in meeting. these requirements.

In line withthe foregoing it is a further object to,,provide a burner of this type having vastly improved mechanical strength and design wherebyany tendency of-the burner body to warp or sag is completely eliminated, even when exposed for long periods to high operating temperatures, thus assuring both uniformity of heating operation and lower replacement cost. The design is such also that local hot-spots? or zones of overheating along, an oven, due to,the crossover pilot flame, can be easily avoided while employing but a single, standard form. of burner body construction. This of course results in.a further economy, as it becomes, unnecessary. to stock diiierenttypes of burners, one type being adaptable for use at any point in an oven.

Briefly, the foregoing objects and advantages are obtained in accordance withthe invention disclosed herein by providing, at one or more points. alongthebody of a multiple-port ribbon burner, an improved integral crossover pilot for cross-igniting, the main burner ports. Un

like prior constructions, the crossover arrangement here:

in disclosed permits the burner body tobe made substantially without transverse interruption, in its wall or web, with the result that the new burner is not subject to the tendency to sag which has characterizedburners of this general type heretofore. As a further measure, longitudinal or dorsal reinforcing ribs running longitudinally of the burner body are provided to increase its transverse strength. A feature of the invention is the provision of a. special shieldat the crossover pointon the burner which permits the employment of a minimum cross-piloting flame but which, owing to the special shielding just men: tioned, nevertheless assures positive travel or propagation of flame from one main port to the other under any oper.

ating condition and by providing the crossover at a point eccentric to the midpoint on the burner length, localized overheating, due to alignment of successive crossover flames in a series of burners along an oven, can be avoided. This is made possible, while employing but a single standard design of burner, by installing burnersin alternate end-for-end arrangement along the oven so as to eiiect a staggering of the position of the crossover flame across the Width of the oven. The staggering effect can of course be further increased by providing more than one available crossover point on the burner body, although only one such point on any particular burner is used.

Specific examples of burners embodyingthe inventive concept are shown in the accompanying drawings and are described hereinafter. These illustrate presently preferred constructions and will serve to facilitate an understanding of the invention as defined in the claims.

In the drawings,

Fig. l is a view in side elevation, partially broken away and partially in section, of a ribbon burner embodying a preferred form of the crossover pilot;

Fig. 2 is an end view, looking from the right, of the burner shown in Fig. 1;

Fig. 3 is a top plan view of the burner shown in Fig. 1, partially broken away and partially in section, the crossover shield and certain other parts having been removed to illustrate structural details of the burner body;

Fig. 4 is a transverse sectional view taken along the line 4-4 of Fig. 1, parts being shown broken away and in section to show details of the crossover pilot;

Fig. 5 is a fragmentary end sectional View taken along the line 5-5 of Fig. 4;

Figs. 6 and 7 show, respectively, detail views in side and end elevation, the latter being partly broken away and in section, of the metal shield employed in the crossover pilot construction shown in Figs. 1 and 4;

Fig. 8 is a fragmentary plan view from below of the shield shown in Fig. 6;

Fig. 9 is a developed view of the shield of Figs. 6 and 7 illustrating a preferred arrangement of the perforations therein;

Fig. 10 is an enlarged sectional view of a jet of the type employed for crossover piloting;

Fig. 11 is a transverse sectional view of a portion of an alternative crossover pilot burner in accordance with the invention which is similar to that used in the preferred embodiment shown in Fig. 4 except for modifications in the type of shield employed;

Fig. 12 is a fragmentary end view in section, taken along the line 12-12 of Fig. 11;

Figs. 13 and 14 illustrate the details of the corrugated metal ribbon used in the alternative shield of Figs. 11 and 12; and

Fig. 15 is a perspective view of burners of the present invention installed in a typical band oven, a portion of the oven enclosure being broken away in the illustration to show the arrangement of the burners therein and the staggering of the crossover pilot positions along the oven.

The preferred form of dual flame gas burner illustrated in Figs. 1 to 5 includes an elongated tubular casing or housing formed from an integral cast iron casing 21. At its respective opposite ends, casing 21 has end walls 22 and 24, each of which has a like, centrally located, tapped aperture 26, 28, respectively. Either one of these apertures is adapted to receive the externally threaded end of a pipe for supplying under pressure a suitable combustible gaseous mixture into the hollow interior 25 of the casing 21, while a matching threaded plug is adapted to be placed inthe opposite end of the casing to close that end against the escape of gaseous fuel thereat. The burner 20 is adapted to be supported at its ends in a horizontal position in a conventional band oven 23, as shown in Fig. 15. As there illustrated, burners 20 are disposed transversely of the oven in a series extending along the oven, and each burner is supplied with a combustible gas mixture from manifolds 30, 32 extending the length of the oven. An endless metal band 33 travels through the oven and carries, in the present instance, goods to be baked on its lower run.

Referring again more particularly to Figs. 1 to 5, the burner casing 21 has on diametrically opposite sides exteriorly offset ribs 34, 36, each extending longitudinally of the casing from a point near one of its ends to a point the same distance from the opposite end. Each of the side ribs 34, 36, is formed with a longitudinal slot 38, 40, respectively, passing through the casing from the interior to the exterior thereof, and extending substantially throughout the length of the ribs, as seen in Fig. 1. These slots 38, 40, constitute the main ports of the burner and each has disposed within it, in face-to-face relationship, a group of transversely corrugated or crimped metal ribbons or hands 42 made of stainless steel or other nonoxidizing material. The design and arrangement of these ribbons is preferably that disclosed in the aforementioned patents to applicant, and they serve to divide the main ports into a series of closely spaced high, medium and low velocity gas jets extending longitudinally throughout the extent of the respective slot 38 or 40. Gaseous fuel escaping through these jets from the interior of casing 21 produces a continuous ribbon or band of flame when the fuel is ignited at the mail burner ports. A conventional high tension sparking electrode 43 (Fig. 3), mounted by suitable clamp means at one side of the burner, is employed to effect ignition of the fuel at one end of main port 38. Once ignited the flame then travels the length of this main burner port and across to the other main port 40 as will presently be described.

The burner casing 21 also includes upper and lower external or dorsal ribs 44, 46, extending longitudinally from a point adjacent one end of the casing to a point similarly spaced from its other end, and upper and lower internal ribs or fins 48, 50, substantially coextensive with the respective external ribs 44, 46. Lower internal fin 50 is continuous throughout its length, while upper fin 48 has an upward relief or depression 49 at two points along its extent, as best seen in Figs. 1 and 5, for fuel distribution purposes, but is otherwise continuous. Additional reinforcing of the casing 21 is supplied by vertical posts or tie ribs 52 which extend transversely of the casing, interiorly thereof, between fins 48 and 50 on either side of depressions 49, as shown in Figs. 1 to 3. .The casing is also provided with internal bafiles 54, 56, adjacent the ends and intermediate the extent of the hollow interior 25 of the casing, which assist in getting proper distribution of gaseous fuel to the several ports.

At points approximately one-third and one-half the distance along the casing 21 from one end thereof, there is provided an integral, arcuate crossover boss 58,. 60, respectively, each of which extends transversely of the burner, externally thereof, between the main ports formed by slots 38, 40. Only one of these bosses, in this instance boss 58, is used on any given burner to provide crossignition from main port 38 to the port 40 when fuel issuing at the former is ignited by means of electrode 43. While as just mentioned, only one of these crossover points is used in any given burner, two such points are made available in order to have but a single design of burner, yet permit the transverse location of the crossover pilot in an oven installation to be staggered along the oven. This will be discussed more fully hereinafter.

Each of bosses 58, 60, on the burner casing 21 comprises an arcuate rib 62 cast integrally with the casing and extending laterally across one-half thereof. This rib serves to increase substantially the wall or web thickness of the burner casing at this point. Rib 62 includes two like semicircular spaced ridges 64 extending along opposite edges of the rib and merging at their opposite ends into the exposed lateral faces of ribs 34, 36 of the casing, as shown more particularly in Figs. 2 and 3 of the drawings. Along the adjacent inner edges of each of the ridges 64 there is a shoulder 66, and between these shoulders, an arcuate web 68 whose external surface is depressed slightly below the horizontal surfaces of shoulders 66. The outer surface of this arcuate web likewise merges at its ends with ribs 34, 36 at the upper edges of slots 38, 40, respectively, in those ribs.

As shown more particularly in Fig. 4, web 68 is drilled to provide an aligned series of evenly spaced radially disposed holes 70 running transversely of the burner substantially throughout the arcuate extent of the web. Each of holes 70 extends through the wall of casing 21 into the interior 25 thereof, and each is counterbored and tapped and has a hollow threaded tip or jet 72 inserted therein. As shown more particularly in Fig. 10, such tips provide narrow orifices 74 for the controlled escape of fuel for cross-piloting purposes.

It will be apparent from the foregoing, and it is an important feature of the invention, that this arrangement does not substantially interrupt the continuous web of the burner casing wall, and the strength of the burner, particularly with respect to transverse bending or sagging, is virtually unaffected.

In order to get propagation of the piloting flame from mousse main port 33', for example, alongthe line. oh piloting jets 72 to the other main port 40,- each crossover'arrangement also includes. an arcuate, perforated: shield 76 of sheet boss. 58 or 60 and is supported onridges-64 in spaced relation to the pilot jets 72 in web 68. Shield 76 is ini-. tially formed from relatively thin flat blank stock. Fig. 9 illustrates a strip of such stockwhich has beenperforated toprovidetwo centrally located parallel rows of equally spaced small holes 78, running throughout theilength of the. strip,- and mounting screw'lioles 80, 82. This stripis then formed intothe arcuate channel shape shown in' Fig. 6, in which the central panel 84 is dropped slightly witharespect to. flanking shoulders 86. Panel 84'extends inra smooth arc throughout the extent of the strip, while shoulders 86 are flattened, as. at'88, at the ends of the strip. In this manner, small protrudinglips 90, 91, are formed by the.centraljpanel 84 at,its opposite ends, the purpose of which will appear more fully' presently.

Shield$ 76is adapted, as mentioned above, to be secured toeither boss. 58i or 60, whichever is selected, and the boss isdrilled and tapped, as at 92, in ridges 64 and on theifaces of ribs. 34, 36, to receivemachinescrews 94.

Theselatterpass through holes 80, 82, of the shield and holdzitflush against the boss. Shoulders186 of. the shield engage ridges 64..and central panel 84 overlies the pilot jets in spaced relation providing a semiannular chamber of flame space 96beneath the shield into which the jets discharge. As will be noted more especially from Fig. 5,

holes 78 in panel 84 are disposed on either side ofthecenter line of the orifices 74 of'jets 72 andextend over the fullrarcuatelengththereof. These holes permit combustion air. to enter the chamber without destroying the bafiiing eifect of the shield in promoting deflection ofthe.

gaseissu'ing from the jets 72: Owing totheprojection. of lips=.90,91, at theends of the shield,chamber96 isopen at. opposite ends. but it is otherwise. closed; except. for

holes 78, by the engagement of flanges 86 on ridgeS64 of the crossover boss.

When a combustible gas is admitted to the burner and high-tensin electric current supplied to the electrode 43, the: gas is ignited at the left hand end of port 38, as viewed in: Figs land 3, and the flame travels to theright along this'port. At the same time gas flows from the several pilot jets 72 under the shield at the crossover point. As thexflame at port 38 reaches the crossover, gas from the jets isignited at the end of the shield 76 where lip 90 projects out over the main port. The flameis picked up at theend of the shield and, supported by combustion air picked up at the lips and flowing in through holes 78, travels from jet to jet beneath the shield until alljets are lighted. At this point, gas issuing from main port 36 is ignited by flash-back from lip 91, and thereafter the flame travels along port- 36 until it is also completely lit. The just described travel of the flame along the main ports and crossover pilot occurs very rapidly, of course; so rapid as. to appear almost instantaneous, depending on how, long the main ports of the burner may be. In any event, the propagation is sufliciently rapid as to ensure against any dangerous accumulation of'unignited fuel, evenwhen the crossover point is remote from the. ignition electrode.

A shield such as shield 76 is essential to'get directed propagationofthe pilot flame just described throughout theextent of the crossover. Without the shield, a sub stantiallycontinuous open crossover port from one main port tothe other is necessary to get the flame to travel acrossthe intervening body of the burner. As previously explained, such a port greatly. weakens, the burner and resultsin its sagging. Moreover, such a port causes a lot more gasto escape at the crossover pilot than is desirable and produces a point on the burner of substantially greater heat output than that at other points along the burner. The employment merely of a series of individual jets, even though quite closely spaced, in order to overcome theforegoing objections, will not produce a depend-.

as well as exteriorly of the central panel 84 of the shield;

but in any event is of very low height compared to prior crossover pilot flames obtained heretofore. While the flame is continuous in the sense that it assures cross-ignition from one end of the crossover to the other, it appears to be flashing rather than a steady flame.

For a better understanding of the invention, a specific example may be helpful. In a burner having an overall length of approximately 41" and a maximum width of 3%" from face to face of ribs 34, 36, the web 68 of the crossover may be provided with nineteen diameter piloting tips or jets 72 spaced 9 apart over the extent of the semicircular web. The orifices in these tips may be on the order of diameter. The width of the chamber 96 formed by ridges 64 may be about while the distance between web 68 and panel 84 may be The shield 76 is preferably of 0.020" stainless sheet steel and differs from the preferred arrangement shown in Figs. 1

through 9 primarily in respect to the form of shield employed. Here, burner 100 has a boss 102 similar to boss 58 previously described except that there is a semiannular recess 104 running centrally of the boss across the interior thereof between main port slots 166, 108; In-

ternal longitudinal reinforcing fins 116, 112, are provided as before, and fin 130 is tapered, as at 114, adjacent each side of recess 104. to allow proper fuel distribution to the crossover jets. The latter are formed by a series of tips 116, equally spaced radially around the central web 118 of the boss, providing metered discharge of gaseous fuel from the individual tips. In place of the unitary perforated metal shield of the preferred construction, a stripof corrugated metal ribbon 120 is employed. This is made to have a width just suflicient to pass between ridges. 12.2 on boss 102 and to lie against and be sup ported by shoulders 124 on the adjacent inner edges of ridges 122. Shoulders 124 hold the ribbon spaced radially outward from the tips 116 to define a semiannular flame space 3.26. The depth of the shoulders below the outer surface of ridges 122 is substantially that of the thickness of the corrugated ribbon 120, and preferably slightly less, and the ribbon is marginally engaged at opposite edges by arcuate hold-down strips 12 8 which are secured by machine screws to the ridges 122. Strips 123 overhang the shoulders 124 so as to confine the corrugated strip 12% between them and the shoulders. Aperturing of the corrugated strip is accomplished by milling or grinding through the peaks or crests of individual corrugations (see Figs. 13 and 14) to provide two series ofaligned holes 132 for the access of combustion air, beneath the shield. And, as in the earlier described embodiment, lips 13 136, are formed at the opposite In opera 78 or 120, of two semicircular strips, similar to hold-down strips 128 in Figs. 11 and 12. By making these strips SlimCiBHllY'WldE so as to extend inwardly toward each other into closely spaced relation, a narrow slit is formed over the pilot tips or jets. While this will provide satisfactory cross-piloting for some purposes, the previously mentioned constructions, particularly that of Figs. 1 through 9, are preferred. It will be readily apparent also that modifications may be made in the specific form of pilot tip employed in the crossover.

In the above description, it has been suggested that the burners be provided with two crossover pilots on its casing, located respectively substantially one-third and one-half the overall length of the burner from one end thereof. This arrangement has the advantage that when a number of such dual gas burners are used in an oven, such as the baking oven of the traveler type illustrated in Fig. 15 for example, if alternate crossover positions are used on adjacent burners, and the latter are turned end-for-end as well, a wide dispersion of the crossover points can be effected in a series of burners and the overheating of particular areas of the travel band thus avoided. This can also be accomplished of course by providing but a single crossover point located eccentrically on the burner, and by reversing alternate burners, or groups of burners. The first arrangement, however, is preferred as it enables one standard design of burner to provide a practical maximum of distribution or staggering of the pilot flames to be eifected along the extent of the oven.

The specific description herein of various embodiments of the invention is to be considered by way of example only and not as limiting the invention. Various changes in form and details of the embodiments illustrated and described may be made, as has been suggested, and all such changes as fall within the scope of the appended claims are to be considered as within the inventive concept.

What is claimed is:

1. The combination, in a ribbon-type gas burner comprising an elongated hollow casting adapted to receive within its interior a gaseous fuel and having spaced parallel main burner ports extending longitudinally of said casting in communication with the interior thereof to permit discharge of said gaseous fuel thereat, and ignition means operatively associated with a first of said main ports; of means for enabling the automatic ignition of the other of said main burner ports from said first, comprising a piloting flame crossover construction extending transversely of said casting between said first and other main burner ports, said construction including a transverse rib section formed integrally with said casting and having a plurality of holes spaced along the extent of said rib section of such size as to leave the body of said casting of substantially continuous web throughout its length, said holes communicating with the interior of said casting and providing a series of individual piloting gas ports for the discharge of gaseous fuel, shielding means extending along and over said piloting ports in spaced relation thereto, said shielding forming with said rib section a channel into which said piloting ports discharge, said channel being open at its opposite ends and said shielding means extending into close overhanging proximity to said main burner ports, said shield being apertured above said piloting ports throughout at least the major portion of their transverse extent, whereby to cause a directed propagation of flame, picked up at the open end of said shield adjacent said first main burner port from ignited fuel issuing thereat, along said series of piloting ports to ignite fuel issuing at said other main burner port at the opposite end of said shield.

2. A gas burner as defined in claim 1, wherein said shield is provided with a plurality of perforations to provide said aperturing, said perforations being offset with respect to the piloting ports beneath them.

. 3. A gas burner as defined in claim 2, wherein said 8 rib section is formed to provide a pair of upstanding walls at either side of said piloting gas ports, and said shielding means includes a metal strip supported by and extending between said walls and over said piloting ports to enclose them laterally, and securing means for fastening said strip on said walls.

4. A gas burner as defined in claim 3, wherein said metal strip is provided at its opposite ends with a projecting lip which overhangs the main burner port adjacent each of its ends.

5. A gas burner as defined in claim 3, wherein said shielding means comprises a unitary metal strip formed with a longitudinally extending, dropped center panel of a width. approximating that of the spacing between said walls of said rib section, saidplurality of perforations being disposed in saidcenter panel.

6. A gas burner as defined in claim 3, wherein said rib section walls are grooved longitudinally thereof to provide a pair of opposed, inwardly extending shoulders, said shielding strip being supported along its opposite under edges on said shoulders, and said strip securing means comprising clamping means attached to either rib wall and engaging the upper edges of said shielding strip.

to clamp it firmly in position against said shoulders.

7. A gas burner as defined in claim 6, wherein'said shielding strip is composed of corrugated metal in which the corrugations run transversely of the extent of said strip, and said plurality of perforations are formed by notching the peaks of the corrugations sufficiently deeply to cut through the strip at said peaks.

8. A gas burner as defined in claim 2, wherein said piloting flame crossover construction is disposed eccentrically of the midpoint along the length of said burner body.

9. A gas burner as defined in claim 2, wherein said burner body has provision for two of said piloting flame crossover constructions, at least one of which is disposed eccentrically of the midpoint along the length of said burner body.

10. In a dual flame ribbon-type gas burner comprising an elongated, hollow, generally cylindrical burner body adapted to receive within its interior a gaseous fuel and having a pair of main burnerports extending longitudinally along opposite sides of said body in communication with the interior thereof to permit the emission of said gaseous fuel, and means for igniting the fuel issuing from a first of said main ports, the improvement in crossover pilot burner means for automatically igniting the other of said main ports from the first which comprises an arcuate web section formed integrally on the burner circumference and extending laterally between said oppositely disposed main burner ports, said arcuate web section having a series of radially disposed pilot jet orifices leading from the interior of said body and opening on the periphery of said web section, said pilot jets being of relatively small size and evenly spaced throughout the extent of said arcuate web section so as to maintain said burner body of substantially uninterrupted longitudinal extent, a radially extending rib along said web section on either side of said orifices, and an arcuate flash-over plate carried by said ribs in spaced, superimposed relation to said orifices, said plate having overhanging lips at each of its ends which project into close proximity to the respectively adjacent main burner ports and having a series of small apertures in its central portion staggered with relation to the jet orifices beneath said plate and extending substantially throughout the length of said plate.

11. A duel flame ribbon-type gas burner as defined in claim 10, wherein said burner body is provided with vertically disposed reinforcing ribs extending longitudinally on its interior substantially throughout the length of said burner.

12. A dual flame ribon-type gas burner as defined in claim 11, which further includes external vertically disis disposed eccentrically of the midpoint along the length of said burnerbody.

References Cited in the file of this patent UNITED STATES PATENTS Munro Mar. 18, 1913 Merrill July 8, 1924 Ensign et a1 Nov. 13, 1951 

